AXPZ20 KNHC 200937
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Wed Feb 20 2019
Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
Based on 0600 UTC surface analysis and satellite imagery through
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
Climatologically, during portions of the months of March and
April of each year, a double ITCZ develops across the eastern
Pacific basin, with a convergence zone of clouds and convection
on either side of the Equator. This pattern has developed in the
past week, while no monsoon trough is present E of 140W.
Currently, a weak surface trough extends from 05.5n85W to 02N91W
to 04.5N110W. The ITCZ in the northern hemisphere extends from
04.5N111W TO 01N123W TO 01.5N130W. Widely scattered moderate
isolated strong convection is within 90 nm N and 180 nm S of the
trough between 83W and 108W. An early season well defined second
ITCZ is noted south of the Equator and enters the forecast area
from 03.4S102W to 02S108W. Associated convection is south of the
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A strong persistent ridge continues to dominate the offshore
forecast waters west of Baja California, extending through
32N133W to beyond the Revillagigedo Islands to near 13N107W. The
remnants of a dissipated cold front have swept SE through the
full length of the Baja Peninsula to 20N today, with the ridge
realigning across the offshore waters of Baja California.
Moderate to fresh NW to N winds will prevail across the waters
west of 108W late this evening through Wed before a new cold
front begins to approach the area from the north Wed night.
Winds will back towards the west and northwest ahead of this. k
The front will sink into the northern waters, Mon increasing to
20-25 kt behind the front as it spreads today across Baja
Seas across the offshore waters have changed little this
afternoon and evening, and are presently 7-11 ft in NW swell.
Seas will gradually subside to 5-8 ft by this afternoon before
the next cold front and associated swell approach the area from
Gulf of California: Moderate to fresh NW winds prevail across
the full length of the Gulf this evening, with seas of 3-5 ft,
except across far north portions where seas are 2-3 ft. Winds
and seas will gradually diminish across north portions through
Wed as winds become southerly in advance of the next cold front.
Winds will then increase across the northern Gulf Wed night
through Fri as this cold front crosses the area. Expect SW to W
winds in the 20 to 30 kt range ahead of the front, with mainly
fresh N winds behind the front. Seas are forecast to build to
near 8 or 9 ft by Thu afternoon.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: Fresh offshore winds are forecast across the
Gulf of Papagayo region throughout the forecast period,
increasing to near 25 kt during the overnight and early morning
hours tonight and beginning again each night starting Fri night.
Seas will build to near 8 ft each early morning due to this
enhanced wind flow.
Gulf of Panama: Mainly gentle to moderate northerly winds are
expected across the Gulf of Panama, with moderate to fresh winds
elsewhere today, and seas of 4 to 6 ft.
REMAINDER OF THE AREA...
A ridge extending SE extensa a high pressure center to near
13N107W. The pressure difference between this ridge and broad
low pressure lingering across the Hawaiian Islands area is
producing a tight pressure gradient across most of the area from
09N to 28N W of 110W, with strongest winds near 25 kt prevailing
from 10N to 23N west of 130W, were seas remain 10-12 ft.
Elsewhere seas generated by these winds combined with long
period NW swell are resulting in an area of seas of 8 ft or
greater covering most of the waters W of 108W. The areal extent
of these winds will diminish over the next couple of days as the
low north of the Hawaiian Islands moves toward the N. The area
of fresh to strong northeast to east winds will persist W of
130W through Thu, with seas slowly subsiding to 8 to 11 ft.